Hi, mate.
Thanks for the video, yes you need a bigger driver.
OR
You gear your small motor down to give you the torque required.
What do the two motors control, do you need high speed?
Getting a motor controller for your big motor, needs some investigation, $137 sounds a bit steep, but we are in interesting times, and local supply at the moment is the only "reliable" source.
Nice Paddle Steamer 
.. how long to build?
Tom... 
PS, going to get lunch..